The Teenage Mutant Ninja Turtles

Very much cheating here, but it's too epic not to mention. In a recent crossover of epic fanboy proportions, the Dark Knight himself teamed up with the Teenage Mutant Ninja Turtles, Splinter, Casey Jones, and more.

This happened via dimension travel of course, and the partnership would end after the Turtles would return home. However, it was a fun adventure that showed the compassion that Batman had for those he called allies. For after becoming partners, and even friends, to the Turtles, he risked everything to get them back home.

To honor his friendship, Raphael gave him his eye cloth to remember them by.